Targeted high-dose radiotherapy benefits inoperable lung cancer patients

Extracranial stereotactic radioablation therapy may prolong survival of frail, medically inoperable patients with stage I non-small cell lung cancer (NSCLC), according to results of a prospective phase I trial.

“Lung cancer patients with multiple health problems are often too frail for conventional radiation therapy or surgery,” lead investigator Dr. Robert Timmerman told Reuters Health. “But even in an extremely frail group of patients we were able to escalate radiation up to a biologically potent dose.”As reported in the November issue of Chest, Dr. Timmerman, at the Indiana University School of Medicine, Indianapolis, and his colleagues evaluated stereotactic radioablation using three-dimensional conformal therapy, which reduces the volume of lung exposed to the treatment. Included were 37 patients ages 56 to 91 years whose tumors were deemed technically resectable and who were followed for up to 30 months.”Doses escalated to very high levels, beyond any previously published experience,” Dr. Timmerman’s group writes, and the maximum tolerated dose “was never reached.” Total doses ranged from 2400 cGy to 6000 cGy delivered in three sessions no more than 8 days apart, with all the patients completing the treatment regimen. Response rate was 87%, including a complete response in 27%. Disease-free survival rate during a median of 15.2 months follow-up was 50%, and overall survival was 64%. “So far, we have treated 50 patients” with doses between 6000 and 6600 cGy, Dr. Timmerman noted, “and only one has had a local recurrence.” Cardiopulmonary function did not decline significantly in the group as a whole, the report indicates, and worsening fibrotic changes in 25 patients encompassed only small fractions of total lung volume. Dr. Timmerman believes that for “marginally resectable” patients, in whom surgery cannot remove the entire tumor, stereotactic radiotherapy may be a better option. Another candidate group comprises patients with small peripheral tumors detected with screening CT, he remarked. “It may be more dangerous to biopsy these patients,” because of adverse effects from the procedure, “than to just treat them with high doses of radiation.”Based on his group’s findings, he added, the NIH is initiating a multicenter study using the same type of therapy.(Source: Chest 2003:124:1946-1955: Reuters Health: Karla Gale: November 12, 2003: Oncolink)